US could mine tailings to meet crit-min demand: study

The United States could meet much of its demand for critical minerals by recovering materials discarded in mining waste, according to a new study from the Colorado School of Mines. 

Published this week in Science, the analysis shows that nearly all critical minerals used in clean energy technologies, electronics and defence applications are already present in ore processed at U.S. mines and the majority end up in tailings. The key question is how to improve waste recovery techniques to make them economically viable. 

The study examined 70 elements across U.S. mining operations. Aside from platinum and palladium, the researchers found that all could theoretically be sourced domestically with improved recovery methods. Elizabeth Holley, associate professor of mining engineering at Colorado School of Mines and lead author of the study, said additional research, development and policy incentives will be needed to make large-scale recovery worthwhile.

“We’re already mining these materials,” she said. “The question is whether we capture them or throw them away.”

Cobalt, germanium

The analysis highlights cobalt and germanium as prime examples. Recovering less than 10% of the cobalt already mined and processed but lost to waste streams would be sufficient to supply the entire U.S. battery market. For germanium, reclaiming under 1% from existing zinc and molybdenum operations would eliminate the need for imports altogether.

The team combined production data from federally permitted U.S. mines with ore concentration data from the U.S. Geological Survey and other international sources to estimate the amount of critical minerals lost in waste streams.

The study comes as the Trump administration is seeking to secure supplies of critical minerals needed for the energy transition, amid concerns about China’s dominant position in mineral production and processing. Recovering minerals from tailings could reduce U.S. dependence on foreign sources and lessen mining’s environmental footprint.